Unstack bar plots in R

In general, the bar plots are used to represent the categorical data. The stacked bar plots are the combined plots where each color represents one group of data. 

The unstacked bar plot is the one where each group of categorical data is represented using different bars and colors instead of stacking upon one on one. In R Programming this type of plot can be implemented using the plot_ly() function present in the plotly package.

Syntax: plot_ly(df,type,marker,labels,values) %>% layout() %>% add_trace()

Where,

• df – data frame
• type – used to specify the type of plot we want to visualize
• marker – used to mark the plot with different colors using color attribute
• labels – names of categorical variables in the dataset
• values – values of the columns in the dataset that we want to plot are specified here (optional)
• layout() –  this function is used to change the layout as required (like assigning a title to the plot)
• add_trace() – this function is used to append similar new traces to existing dimension

Let’s install and load the plotly library with the help of below commands

install.packages("plotly")
library(plotly)

Unstack bar plot for two columns 

In this, we will be creating a data frame which contains 2 columns and then we will be using plotly module to plot the unstacked bar plot.

R

# Creation of sample data frame (Placement Statistics)
data <- data.frame(
  Branches<-c('CSE','ECE','MECH','EEE','CIVIL'),
  Placements_2021 <-c(99,98,89,90,75),
  Placements_2022 <- c(95,94,93,85,77))

# Plotting the unstacked bar plot using plot_ly
fig <- plotly::plot_ly(data,x = ~Branches,y=~Placements_2022,
                       type = 'bar', name = '2022') %>%
       add_trace(y=~Placements_2021,name = '2021') %>%
       layout(yaxis = list(title = 'Placements_Count'),
              barmode = 'unstack',title="Placement Statistics")

fig

Output:

Unstack bar plot for more than two columns

We can also implement the unstack bar plotting for more than 2 columns. Let’s see the code for it.

R

# Creation of sample data frame (Placement Statistics)
data <- data.frame(
  Languages<-c('Python','R','C++','Java','Ruby'),
  Batch_2020 <-c(199,398,319,910,735),
  Batch_2021 <- c(952,942,933,851,771),
  Batch_2022 <- c(1022,982,983,811,721))

# Plotting the unstacked bar plot using plot_ly
fig <- plotly::plot_ly(data,x = ~Languages,y=~Batch_2020,
                       type = 'bar', name = '2020') %>%
       add_trace(y=~Batch_2021,name = '2021') %>%
        add_trace(y=~Batch_2022,name = '2022') %>%
       layout(yaxis = list(title = 'Students_Count'),
              barmode = 'unstack',title="Student Statistics")

fig

Output: